奇怪的classCastException hibernate 3.5 glassfish [英] Strange classCastException hibernate 3.5 glassfish

问题描述

我有一个问题，我无法自己解决。
我有一个war文件打包在ear中，并且运行在glassfish 3.0.1上，并且hibernate 3.5作为JPA provider。我用maven编译它，并用想法或手动部署它。
每隔一段时间，我都会在DAO中获得一个强制转换异常：

  java.lang.ClassCastException：com.myproject。 domain.entity.User不能转换为
 com.myproject.domain.entity.User 
  

其他时候，它工作得很好。这种行为没有模式。
有人会对这里发生的事情有所了解吗？

在com.myproject.domain.dao处引发异常
的示例方法。 UserDAOImpl.checkUserSessionValid（UserDAOImpl.java:195）

  public User checkUserSessionValid（String sessionId）{
 User user = null ; 
 EntityManager em = provider.entityManager（）; 
 
尝试{
 em.getTransaction（）。begin（）; 
 // Query q = em.createQuery（SELECT u FROM User u WHERE u.session.sessionId =：sessionId）;没有什么区别：/ 
 Query q = em.createQuery（SELECT u FROM User u WHERE u.session.sessionId =：sessionId，User.class）; 
 q.setParameter（sessionId，sessionId）; 
 user =（User）q.getSingleResult（）; 
 
 em.getTransaction（）。commit（）; 
} catch（NoResultException忽略）{
 
} finally {
 em.close（）; 
} 
 
返回用户; 
} 
 
我的图书馆
 [信息] +  -  org.apache.geronimo.specs：geronimo-jpa_2.0_spec：jar：1.0：提供
 [信息] +  -  javax.validation：validation-api：jar：1.0.0.GA：编译
 [INFO] +  -  org.hibernate：hibernate-annotations：jar：3.5.1-Final：compile 
 [ INFO] | +  -  org.hibernate：hibernate-core：jar：3.5.1-Final：编译
 [INFO] | | +  -  antlr：antlr：jar：2.7.6：编译
 [INFO] | | +  -  commons-collections：commons-collections：jar：3.2.1：编译
 [INFO] | | +  -  dom4j：dom4j：jar：1.6.1：编译
 [INFO] | | | \ -xml-apis：xml-apis：jar：1.0.b2：compile 
 [INFO] | | javax.transaction：jta：jar：1.1：提供（作用域由编译管理）
 [INFO] | +  -  org.hibernate：hibernate-commons-annotations：jar：3.2.0.Final：compile 
 [INFO] | +  -  org.hibernate.javax.persistence：hibernate-jpa-2.0-api：jar：1.0.0.Final：compile 
 [INFO] | \- org.slf4j：slf4j-api：jar：1.5.2：编译
 [INFO] +  -  org.hibernate：hibernate-entitymanager：jar：3.5.1-Final：编译
 [INFO ] | +  -  cglib：cglib：jar：2.2：编译
 [INFO] | | \  -  asm：asm：jar：3.1：编译
 [INFO] | \ javassist：javassist：jar：3.9.0.GA：编译
 [INFO] +  -  org.hibernate：hibernate-validator：jar：4.1.0.Final：compile 
 [INFO] + -  org.slf4j：slf4j-simple：jar：1.5.2：test 
 [INFO] +  -  mysql：mysql-connector-java：jar：5.1.13：test 
 [INFO] +  -  org .hsqldb：hsqldb：jar：2.0.0：test 
  

解决方案

对于通过谷歌来到这里的所有人来说，这个问题出现在4.3.6及以上： https： //http：//hibernate.atlassian.net/browse/HHH-9446

降级到Hibernate 4.3.5为我们的团队提供了技巧。

Hi I have a problem that I can't solve on my own. I have a war file packaged in ear and running on glassfish 3.0.1 with hibernate 3.5 as JPA provider. I compile it with maven and deploy it with idea or manually. Every other time I get a cast exception in my DAOs:

java.lang.ClassCastException: com.myproject.domain.entity.User cannot be cast to 
com.myproject.domain.entity.User

Other times it works perfectly fine. There is no pattern in this behaviour. Could someone shine some light on what is happening here?

Example method where the exception was thrown at com.myproject.domain.dao.UserDAOImpl.checkUserSessionValid(UserDAOImpl.java:195)

public User checkUserSessionValid(String sessionId) {
        User user = null;
        EntityManager em = provider.entityManager();

        try {
            em.getTransaction().begin();
           //Query q = em.createQuery("SELECT u FROM User u WHERE u.session.sessionId = :sessionId"); makes no difference :/
            Query q = em.createQuery("SELECT u FROM User u WHERE u.session.sessionId = :sessionId",User.class);
            q.setParameter("sessionId", sessionId);
            user = (User) q.getSingleResult();

            em.getTransaction().commit();
        } catch (NoResultException ignored) {

        } finally {
            em.close();
        }

        return user;
 }

My libraries
[INFO] +- org.apache.geronimo.specs:geronimo-jpa_2.0_spec:jar:1.0:provided
[INFO] +- javax.validation:validation-api:jar:1.0.0.GA:compile
[INFO] +- org.hibernate:hibernate-annotations:jar:3.5.1-Final:compile
[INFO] |  +- org.hibernate:hibernate-core:jar:3.5.1-Final:compile
[INFO] |  |  +- antlr:antlr:jar:2.7.6:compile
[INFO] |  |  +- commons-collections:commons-collections:jar:3.2.1:compile
[INFO] |  |  +- dom4j:dom4j:jar:1.6.1:compile
[INFO] |  |  |  \- xml-apis:xml-apis:jar:1.0.b2:compile
[INFO] |  |  \- javax.transaction:jta:jar:1.1:provided (scope managed from compile)
[INFO] |  +- org.hibernate:hibernate-commons-annotations:jar:3.2.0.Final:compile
[INFO] |  +- org.hibernate.javax.persistence:hibernate-jpa-2.0-api:jar:1.0.0.Final:compile
[INFO] |  \- org.slf4j:slf4j-api:jar:1.5.2:compile
[INFO] +- org.hibernate:hibernate-entitymanager:jar:3.5.1-Final:compile
[INFO] |  +- cglib:cglib:jar:2.2:compile
[INFO] |  |  \- asm:asm:jar:3.1:compile
[INFO] |  \- javassist:javassist:jar:3.9.0.GA:compile
[INFO] +- org.hibernate:hibernate-validator:jar:4.1.0.Final:compile
[INFO] +- org.slf4j:slf4j-simple:jar:1.5.2:test
[INFO] +- mysql:mysql-connector-java:jar:5.1.13:test
[INFO] +- org.hsqldb:hsqldb:jar:2.0.0:test

解决方案

For all of you coming here via google, this problem is present in 4.3.6 and up: https://hibernate.atlassian.net/browse/HHH-9446

Downgrading to Hibernate 4.3.5 did the trick for our team.

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